Lexus 2004 LS430 Owner's Manual page 355

D The laser radar sensor automatically detects dirt if it
is sticking to the sensor glass of your vehicle, and if
detected, a message is shown
multi-information display. However, if the sensor
glass is covered with a transparent or translucent
vinyl bag, icicle, etc., dirt may not be detected,
resulting in improper vehicle-to-vehicle distance.
Continue driving with due care to the vehicle ahead.
If dirt is detected, the dynamic laser cruise control
function is automatically cancelled. Always keep the
sensor glass clean.
Dynamic laser cruise control should not be used in the
following conditions, to avoid serious injury or death.
on the
D In bad weather (such as rain, fog, snow, sandstorms
or direct sunlight, or when raindrops or snowflakes
get in the laser
vehicle-to-vehicle distance will not be measured
accurately.
If the wipers are operated at high or low speeds
(including the high and low speed operation with the
wiper lever in the "AUTO" position), dynamic laser
cruise control is automatically cancelled. (In the case
of intermittent wiper operation, it is not cancelled.)
Dynamic laser cruise control is automatically
cancelled when the measurement is extremely
unstable due to bad weather.
D On the roads in heavy traffic or at sharp bends:
As an appropriate speed cannot be maintained,
serious injury or death could result.
D On slippery road surfaces (icy or snow-covered road
surfaces):
The tires will race and you will be unable to control.
STARTING AND DRIVING
radar sensor glass), the
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